A McCandless mother told Allegheny County police Tuesday that she heard "crazy voices" and then pushed her two young sons down into a bathtub of water and sat on them thinking she could send them to heaven, according to court documents.

Laurel Michelle Schlemmer, a 40-year-old former teacher now charged with homicide, told detectives she thought she could have been a better mother to her oldest son if "the other two boys weren't around and they would be better off in heaven."

One of the boys died after Tuesday's incident and the other was hospitalized in critical condition.

KDKA video: Neighbors stunned by McCandless tragedy

Ms. Schlemmer got out of the tub, replaced her wet clothes with dry ones and put them in a trash bag that she carried to the garage, along with two towels, police wrote in a criminal complaint. Ms. Schlemmer returned to the bathroom, pulled her 3- and 6-year-old sons out of the tub and placed them on the floor next to it and called 911, police said.

"[Ms.] Schlemmer said she never attempted CPR because she did not know how to do it," police wrote in a criminal complaint.

Tuesday night, she was being held in the Allegheny County Jail while she awaited arraignment on charges of homicide, aggravated assault and other crimes.

Her 3-year-old son, Luke Schlemmer, died at UPMC Passavant about 10:50 a.m., roughly an hour after police arrived at the family's home in the 9500 block of Saratoga Drive.

His 6-year-old brother, Daniel Schlemmer, remained in critical condition at Children's Hospital of Pittsburgh of UPMC. A third boy, a 7-year-old, was at school at the time.

Ms. Schlemmer's father, Donald Ludwig, declined to comment Tuesday evening after he met with police. Her husband, Mark Schlemmer, and his relatives could not be reached for comment.

To those who lived near the Schlemmer house all seemed fine before Tuesday morning. Laurel and Mark Schlemmer married in July of 2005 in Grove City. He worked as an actuary and she as a teacher, according to their marriage license. In recent years, Ms. Schlemmer was a stay-at-home mother, neighbors said.

The couple bought their two-story colonial home on Saratoga Drive in May 2006, according to county real estate records.

Neighbor Bob Majersky said he spotted Ms. Schlemmer playing Frisbee in the front yard with her sons Monday evening.

"If this hadn't happened today, the kids would have been out here playing a pick-up ball game," he said Tuesday night.

He described the Schlemmers as a wonderful family that did not exhibit any outward signs of trouble.

"Can you image that dad?" Mr. Majersky said. "It's a regular Tuesday, and he gets a call: 'Your children were found unresponsive in the tub.' "

Court records show police expressed concern about Ms. Schlemmer's interaction with a child in at least one instance before.

Ross police cited Ms. Schlemmer in September of 2009 with a summary offense of leaving a child unattended in a car, and she was found guilty.

A Ross police report from the time indicates that police found the child, who was not named in the report, unattended inside a Honda Odyssey parked at the Ross Park Mall shortly after noon on Sept. 5, 2009. They estimated that the child had been alone for about 20 minutes.

"The windows were part way down and officers were able to open the door to let the vehicle cool," police wrote. "Officers were able to take a heat gun and get a Temp reading of 112 degrees inside the vehicle."

They noted that the child was "OK."

Ross police said Tuesday they did not have any information indicating which child was in the car.

Neighbors Tuesday struggled to reconcile their memories of the Schlemmer family as a peaceful, normal family with the news of the incident.

"We're sick. We're just sick about it," neighbor Mary Lou Lioi said.

Liz Navratil: lnavratil@post-gazette.com, 412-263-1438 or on Twitter @LizNavratil. Molly Born contributed. First Published April 1, 2014 11:39 AM